Edge-sealed window films and methods

Abstract

Transparent edge sealed window films substantially minimize (if not eliminate entirely) degradative effects on the window film, particularly solar-reflecting metals and/or oxides associated with multilayer window films, caused by ambient conditions (e.g., commercial window cleaners, salt and the like). The edges of window films are preferably sealed by a liquid solvated polymeric material which, upon curing, provides a solid transparent seal which significantly minimizes the degradative effects of the ambient environment. Most preferably, the window film whose edges are sealed will include a transparent thermoplastic (e.g., a polyester) film layer and a solar-reflecting metal and/or oxide applied onto a surface of the film layer. The sealant for such a preferred window film will be a polyester-type sealant which has silane end-group functionality and substantially no free isocyanate groups.

What is claimed is:  
     
       1. A window comprising: 
       a window frame;  
       window glass mounted in said window frame;  
       a solar film adhered to the window glass and having an edge which is spaced from said window frame so as to establish a boundary region of exposed window glass therebetween; and  
       an edge sealant applied over said edge of said solar film and at least a portion of said boundary region of said exposed glass substrate, wherein  
       said window film includes a polyester film layer and at least one metal or metal oxide solar coating on said polyester film layer; and wherein  
       said edge sealant is a cured transparent residue of the reaction product of a thermoplastic resin and a silane containing a free isocyanate group, said edge sealant being chemically bonded to said polyester film layer, said at least one metal or metal oxide solar coating on said polyester film layer and said portion of said boundary region of said exposed glass substrate, and being bonded to an adjacent portion of said window frame so as to form a seal between said edge of said solar film and window frame which thereby resists ambient degradative effects on said metal or metal oxide solar coating.  
     
     
       2. The window of claim  1 , wherein said silane is gamma-isocyanatropropyltriethoxy silane. 
     
     
       3. The window of claim  1 , wherein the edge sealant is the reaction product of (i) a dibasic acid selected from the group consisting of terephthalic acid, isophthalic acid, and hexahydrophthalic acid, and mixtures thereof, with (ii) a polymethylene glycol of the formula HO(CH 2 ) x OH, where x is an integer from 2 to 10, neopentyl glycol and glycerine, and mixtures thereof, and (iii) an aliphatic dibasic acid selected from the group consisting of those having the formula HOOC(CH 2 ) n COOH where n is an integer from 1 to 8, and mixtures of such acids. 
     
     
       4. The edge-sealed window film of claim  1  or  3 , having silane end group functionality and substantially no free NCO groups.